Besides, because of high PD-L1 expression include expression in mRNA level is associated with good clinical outcome of anti-PD-1/PD-L1 therapy (Patel and Kurzrock, 2015; Schmid et al., 2016), we could suggest that PD-1/PD-L1 checkpoint inhibitor therapy might improve outcome of breast cancer patients who have an increased PD-L1 expression after completion of chemotherapy or hormonal therapy. Here, CD274 is linked to breast cancer.